I think you can buy them at Mike's and HL, but I'm not sure. I've never had to buy an envelope. When I first started making cards I was a girl scout leader. A card store went out of business and gave our group all the stuff they were going to throw away. I grabbed all the packaged invites, thank you's and such. Threw out the ugly cards and kept all the envelopes. I bet I had 2,000 at one point.